function isUserName(str) {  
	var result = str.match(/^[a-z][a-z0-9_]{4,19}$/i);   
    if (result == null)  
        return false;          
    return true;
}

function isPassWord(str) {  
	var result = str.match(/^[a-zA-Z0-9_\!\@\.]{5,}$/);   
    if (result == null)  
        return false;
    return true;
} 